Technical Field
[0001] The present invention relates to liquid ejecting apparatuses such as inkjet printers
that eject liquid onto a medium, liquid ejectingmethods, and liquid ejecting systems.
Background Art
[0002] Inkjet printers are known as one type of liquid ejecting apparatus that ejects liquid
toward a medium. The inkjet printer is configured so as to perform printing by ejecting
ink, as the liquid, onto a medium such as paper. Recent-type inkjet printers are provided
with a print function known as "borderless printing". "Borderless printing" refers
to a printing method in which ink is applied up to the very edge of the medium to
perform printing such that no blank space is formed on the medium. The ink that is
ejected up to the very edge of the medium may miss the medium due to positional misalignment
of the medium, for example. Thus, such printers are provided with a recovery section
for recovering the ink that has been discarded. The recovery section may, for example,
be provided with an absorbing material that is configured so as to absorb the ink
that has missed the medium, such as a sponge, and the ink that is recovered is absorbed
by the absorbing material and held therein.
[0003] However, such "borderless" printing has the following problems: among the inks that
are ejected, there are types that have low permeability or that easily solidify, for
example. When such ink misses the medium during "borderless" printing and reaches
the top of the absorbing material of the ink recovery part, there is a possibility
that the ink will not easily permeate into the absorbing material but instead remain
as it is on the surface. In such a case, if ink is subsequently discarded on top of
the remaining ink and remains thereon without readily permeating, the problem of a
continuing accumulation of ink on the absorbing material arises. When ink accumulates
and is piled up in this manner, discarded ink sequentially piles up on the absorbing
material, and may eventually cause problems such as soiling of the printing medium
and adversely affecting the movement of the head. Particularly, in recent years, printing
technology has been proposed that uses special reacting liquids to accelerate coagulation
of the ink to improve color saturation in order to achieve increased image quality.
If such reacting liquids are used, then coagulation of the ink continues, and the
accumulation amount may further increase. This has been a problem.
[0004] The present invention has been made in light of the foregoing issues, and it is an
object thereof to reduce the occurrence of problems such as build up of liquid such
as ink that has reached a region outside the medium during, for example, "borderless
printing".
Disclosure of Invention
[0005] A principal aspect of the invention for achieving the foregoing object is a liquid
ejecting apparatus comprising: liquid ejecting means that ejects a plurality of types
of liquid toward a medium; and ejection control means that controls ejection of the
liquid from the liquid ejecting means; wherein when the liquid ejecting means attempts
to eject the liquid into a region that is outside the medium, the ejection control
means prevents one or more types of liquid, of among the plurality of types of liquid,
from being ejected into the region that is determined to be outside the medium.
[0006] Other features of the present invention will become clear through the present specification
and descriptions in the accompanying drawings.
Brief Description of Drawings
[0007]
Fig. 1 is a perspective view showing an embodiment of an inkjet printer.
Fig. 2 is an explanatory diagram of the overall structure of the inkjet printer.
Fig. 3 is a diagram showing the carriage etc. of the inkjet printer.
Fig. 4 is a diagram showing the carrying mechanism of the inkjet printer.
Fig. 5 is an explanatory diagram showing the arrangement of nozzles in the head.
Fig. 6 is a block diagram showing the configuration within the head drive circuit.
Fig. 7 is an explanatory diagram for describing processing on the host side.
Fig. 8 is an explanatory diagram that describes the relationship between the print
region and the paper during normal printing.
Fig. 9 is an explanatory diagram that describes the relationship between the print
region and the paper during borderless printing.
Fig. 10 is a cross-sectional view showing the ink recovery section.
Fig. 11 is a plan view showing the ink recovery section.
Fig. 12 is an explanatory diagram that describes the print region of the ink when
the ejection amount is reduced.
Fig. 13 is an explanatory diagram that describes the print region of the ink when
the ejection amount is set to zero.
Fig. 14 is an explanatory diagram that describes one example of another method for
borderless printing.
Fig. 15 is an explanatory diagram that describes an example of a method for reducing
the amount of ink that is ejected in another method for borderless printing.
Fig. 16 is an explanatory diagram showing an example of a method for verifying the
permeability of the ink.
Fig. 17 is a structural diagram of the external appearance of a computer system.
Fig. 18 is a block diagram showing a configuration of the computer system.
[0008] A legend of the main reference numerals used in the drawings is shown below.
- 1
- inkjet printer
- 2
- control panel
- 3
- paper discharge section
- 4
- paper supply section
- 5
- control button
- 6
- display lamp
- 7
- paper discharge tray
- 8
- paper supply tray
- 10
- paper carrying unit
- 11A
- paper insert opening
- 11B
- roll paper insert opening
- 13
- paper supply roller
- 14
- platen
- 15
- paper feed motor (PF motor)
- 16
- paper feed motor driver (PF motor driver)
- 17A
- carry roller
- 17B
- paper discharge roller
- 18A
- free roller
- 18B
- free roller
- 20
- ink ejection unit
- 21
- ejection head
- 211
- nozzle row
- 22
- head driver
- 221
- original drive signal generation section
- 222
- mask circuit
- 223
- drive signal correction circuit
- 30
- cleaning unit
- 31
- pump device
- 32
- pump motor
- 33
- pump motor driver
- 35
- capping device
- 40
- carriage unit
- 41
- carriage
- 42
- carriage motor (CR motor)
- 43
- carriage motor driver (CR motor driver)
- 44
- pulley
- 45
- timing belt
- 46
- guide rail
- 48
- ink cartridge
- 49
- ink cartridge
- 50
- measuring instrument group
- 51
- linear encoder
- 52
- rotary encoder
- 53
- paper detection sensor
- 53A
- lever
- 54
- paper width sensor
- 541
- light-emitting section
- 543
- light-receiving section
- 60
- control unit
- 61
- CPU
- 62
- timer
- 63
- interface section
- 64
- ASIC
- 65
- memory
- 66
- DC controller
- 67
- host computer
- 80
- ink recovery section
- 82
- groove section
- 84
- absorbing material
- 90
- computer
- 91
- video driver
- 93
- display device
- 95
- application program
- 96
- printer driver
- 97
- resolution conversion module
- 98
- color conversion module
- 99
- halftone module
- 100
- rasterizer
- 101
- user interface display module
- 102
- UI printer interface module
- 1000
- computer system
- 1102
- computer
- 1104
- display device
- 1106
- printer
- 1108
- input device
- 1108A
- keyboard
- 1108B
- mouse
- 1110
- reading device
- 1110A
- flexible disk drive device
- 1110B
- CD-ROM drive device
- 1202
- internal memory
- 1204
- hard disk drive unit
- S
- medium (paper)
- P
- print region
- P1
- normal ejection region
- P2
- ejection amount reduction region
Best Mode for Carrying Out the Invention
[0009] At least the following matters will be made clear by the description in the present
specification and the accompanying drawings.
[0010] A liquid ejecting apparatus comprises:
a liquid ejecting section that ejects a plurality of types of liquid toward a medium;
wherein among the liquids that are ejected from the liquid ejecting section and
that reach a region that is outside the medium, an ejection amount of one or more
types of the liquid is reduced.
[0011] According to such a liquid ejecting apparatus, it is possible to achieve a reduction
in problems caused when some types of liquid, from among the plurality of liquids,
reach the region that is outside the medium.
[0012] Furthermore, in this liquid ejecting apparatus, among the liquids that are ejected
from the liquid ejecting section and that reach the region that is outside the medium,
an ejection amount of the one or more types of the liquid may be reduced such that
the amount becomes zero.
[0013] According to such a liquid ejecting apparatus, if the ejection amount of some types
of liquid is reduced such that it becomes zero, then a further reduction of problems
can be achieved.
[0014] Furthermore, in this liquid ejecting apparatus, the one or more types of the liquid
may include a liquid whose permeability is lower than another type of liquid that
is ejected from the liquid ejecting section.
[0015] According to such a liquid ejecting apparatus, problems caused when a liquid whose
permeability is low reaches the region that is outside the medium can be reduced.
[0016] Furthermore, in this liquid ejecting apparatus, the one or more types of the liquid
may include a liquid whose permeability is the lowest of all of the types of the liquids
that are ejected from the liquid ejecting section.
[0017] According to such a liquid ejecting apparatus, problems caused when a liquid whose
permeability is the lowest of all reaches the region that is outside the medium can
be reduced.
[0018] Furthermore, in this liquid ejecting apparatus, the one or more types of the liquid
may include a liquid whose permeability decreases on contact with another type of
liquid that is ejected from the liquid ejecting section.
[0019] According to such a liquid ejecting apparatus, problems caused when a liquid whose
permeability decreases when coming into contact with another type of liquid reaches
the region that is outside the medium can be reduced.
[0020] Furthermore, in this liquid ejecting apparatus, the one or more types of the liquid
may include a liquid that lowers a permeability of another type of liquid that is
ejected from the liquid ejecting section on contact therewith.
[0021] According to such a liquid ejecting apparatus, problems caused when a liquid that
lowers the permeability of another type of liquid when coming into contact with the
other type of liquid reaches the region that is outside the medium can be reduced.
[0022] Furthermore, in this liquid ejecting apparatus, the one or more types of the liquid
may include a liquid that accelerates coagulation of another type of liquid that is
ejected from the liquid ejecting section.
[0023] According to such a liquid ejecting apparatus, problems caused when a liquid that
accelerates coagulation of another type of liquid reaches the region that is outside
the medium can be reduced.
[0024] Furthermore, in this liquid ejecting apparatus, there may be a plurality of types
of the one or more types of the liquid.
[0025] According to such a liquid ejecting apparatus, problems caused when the liquids reach
the region that is outside the medium can be reduced for the plurality of types of
liquids.
[0026] Furthermore, in this liquid ejecting apparatus, it is also possible to provide a
liquid recovery section that recovers liquid that has missed the medium.
[0027] According to such a liquid ejecting apparatus, liquid that has missed the medium
can be recovered.
[0028] Furthermore, in this liquid ejecting apparatus, it is possible to provide a liquid
recovery section that recovers liquid that has missed the medium; and the liquid recovery
section may be provided with an absorbing material for absorbing the liquid that has
been recovered.
[0029] According to such a liquid ejecting apparatus, by providing the absorbing material,
the liquid that is recovered can be absorbed with the absorbing material and held
therein.
[0030] Furthermore, in this liquid ejecting apparatus, the liquid may be ink.
[0031] According to such a liquid ejecting apparatus, problems caused when the ink from
the liquid ejecting section reaches the region that is outside the medium can be reduced.
[0032] Further, a liquid ejecting apparatus comprises:
a liquid ejecting section that ejects a plurality of types of liquid toward a medium;
and
an ejection control section that controls ejection of the liquid from the liquid ejecting
section;
wherein when the liquid ejecting section attempts to eject the liquid into a region
that is determined to be outside the medium, the ejection control section prevents
one or more types of liquid, of among the plurality of types of liquid, from being
ejected into the region that is determined to be outside the medium.
[0033] According to such a liquid ejecting apparatus, when the liquid ejecting section attempts
to eject the liquid into a region that is outside the medium, by not ejecting, into
that region, one or more types of liquid of among the plurality of types of liquids,
it is possible to avoid adverse influences caused when those types of liquid have
missed the medium.
[0034] Further, a liquid ejecting method of ejecting a plurality of types of liquid toward
a medium, comprises:
reducing an ejection amount of one or more types of the liquid of among the liquids
that are ejected and that reach a region that is outside the medium.
[0035] According to such a liquid ejecting method, it is possible to achieve a reduction
in problems caused when some types of liquid, from among the plurality of types of
liquids, reach the region that is outside the medium.
[0036] Further, a liquid ejecting system comprises:
a computer; and
a liquid ejecting apparatus that is connectable to the computer;
wherein the liquid ejecting apparatus includes: a liquid ejecting section that
ejects a plurality of types of liquid toward a medium; wherein among the liquids that
are ejected from the liquid ejecting section and that reach a region that is outside
the medium, an ejection amount of one or more types of the liquid is reduced.
[0037] According to such a liquid ejecting system, it is possible to achieve a reduction
in problems caused when some types of liquid, from among the plurality of types of
liquids, that are ejected from the liquid ejecting apparatus reach the region that
is outside the medium.
=== Overview of Liquid Ejecting Apparatus ===
[0038] An overview of an inkjet printer serving as an example of a liquid ejecting apparatus
according to the present invention is described. Fig. 1 to Fig. 5 are diagrams for
describing the overview of an embodiment of an inkjet printer 1. Fig 1 shows the external
appearance of an embodiment of the inkjet printer 1. Fig. 2 shows a block configuration
of the inkjet printer 1, and Fig. 3 shows a carriage of the inkjet printer 1 and a
surrounding section of the carriage. Fig. 4 shows a carry section of the inkjet printer
1 and a surrounding section of the carry section, and Fig. 5 shows a drive mechanism
of the carry section of the inkjet printer 1.
[0039] As shown in Fig. 1, the inkjet printer 1 is provided with a structure in which a
medium (medium to be printed) such as print paper that is supplied from the rear side
is discharged from the front side. A control panel 2 and a paper discharge section
3 are arranged at the front side section, and a paper supply section 4 is provided
at the rear side section. The control panel 2 is provided with various types of control
buttons 5 and display lamps 6. The paper discharge section 3 is provided with a paper
discharge tray 7 that blocks the paper discharge opening when the printer is not in
use. A paper supply tray 8 is arranged at the paper supply section 4 to hold cut paper
(not shown). It should be noted that the inkjet printer 1 may be provided with a paper
feed structure that is capable of being used in printing not only print paper in single
sheets, such as cut paper, but also media that are continuous, such as roll paper.
[0040] As shown in Fig. 2, the inkjet printer 1 is provided with a paper carrying unit 10,
an ink ejection unit 20, a cleaning unit 30, a carriage unit 40, a measuring instrument
group 50, and a control unit 60 as its primary components.
[0041] The paper carrying unit 10 is for feeding a medium such as paper, which is an example
of a printing medium, into a printable position and making the paper move in a predetermined
direction (the direction perpendicular to the paper face in Fig. 2 (hereinafter, this
is referred to as the paper carrying direction)) by a predetermined movement amount
during printing. That is to say, the paper carrying unit 10 functions as a carrying
mechanism for carrying media such as paper. As shown in Fig. 4, the paper carrying
unit 10 has a paper insert opening 11A and a roll paper insert opening 11B, a paper
supply motor (not shown), a paper supply roller 13, a platen 14, a paper feed motor
(hereinafter referred to as PF motor) 15, a paper feed motor driver (hereinafter,
referred to as PF motor driver) 16, a carry roller 17A and paper discharge rollers
17B, and free rollers 18A and free rollers 18B. However, the paper carrying unit 10
does not necessarily have to include all of these structural elements in order to
function as a carrying mechanism.
[0042] The paper insert opening 11A is where paper S, which is a medium, is inserted. The
paper supply motor (not shown) is a motor for carrying the paper S that has been inserted
through the paper insert opening 11A into the printer 1, and is constituted by a pulse
motor. The paper supply roller 13 is a roller for automatically carrying the paper
that has been inserted into the paper insert opening 11A or 11B into the printer,
and is driven by the paper supply motor. The paper supply roller 13 has a transverse
cross-sectional shape that is substantially the shape of the letter D. The peripheral
length of a circumference section of the paper supply roller 13 is set longer than
the carrying distance to the PF motor 15, so that using this circumference section,
the medium to be printed can be carried up to the PF motor 15. It should be noted
that a plurality of media are kept from being supplied at one time by the rotational
drive force of the paper supply roller 13 and the frictional resistance of separation
pads (not shown).
[0043] The platen 14 is a supporting means that supports the paper S during printing. The
PF motor 15 is a motor for feeding the medium, for example paper, in the paper carrying
direction, as shown in Fig. 2 and Fig. 4, and is constituted by a DC motor. The PF
motor driver 16 is for driving the PF motor 15. The carry roller 17A is a roller for
feeding the paper S that has been carried into the printer 1 by the paper supply roller
13 to a printable region, and is driven by the PF motor 15. The free rollers 18A (see
Fig. 4 and Fig. 5) are provided in a position that is in opposition to the carry roller
17A, and they push the paper S toward the carry roller 17A by sandwiching the paper
S between them and the carry roller 17A.
[0044] The paper discharge rollers 17B (see Fig. 4) are rollers for discharging the paper
S for which printing has finished, to outside the printer. The paper discharge rollers
17B are driven by the PF motor 15 through a gear wheel that is not shown in the drawings.
The free rollers 18B are provided in a position that is in opposition to the paper
discharge rollers 17B, and they push the paper S toward the paper discharge rollers
17B by sandwiching the paper S between them and the paper discharge rollers 17B.
[0045] The ink ejection unit 20 is for ejecting ink onto media, for example paper. As shown
in Fig. 2, the ink ejection unit 20 has an ejection head 21 and a head driver 22.
The ejection head 21 has a plurality of nozzles, which are ink ejecting sections,
and ejects ink intermittently from each of the nozzles. The head driver 22 is for
driving the ejection head 21 so that ink is ejected intermittently from the ejection
head 21.
[0046] The cleaning unit 30 is for keeping the nozzles of the ejection head 21 from becoming
clogged, as shown in Fig. 3. The cleaning unit 30 has a pump device 31 and a capping
device 35. The pump device 31 is for extracting ink from the nozzles in order to prevent
the nozzles of the ejection head 21 from becoming clogged, and has a pump motor 32
and a pump motor driver 33. The pump motor 32 sucks out ink from the nozzles of the
ejection head 21. The pump motor driver 33 drives the pump motor 32. The capping device
35 is for sealing the nozzles of the ejection head 21 when printing is not being performed
(during standby) so that the nozzles of the ejection head 21 are kept from clogging.
[0047] The carriage unit 40 is for scan moving the ejection head 21 in a predetermined direction
(in Fig. 2, the left and right direction of the paper face (hereinafter, this is referred
to as the scanning direction)), as shown in Fig. 2 and Fig. 3. The carriage unit 40
has a carriage 41, a carriage motor (hereinafter, referred to as CR motor) 42, a carriage
motor driver (hereinafter, referred to as CR motor driver) 43, a pulley 44, a timing
belt 45, and a guide rail 46. The carriage 41 can be moved in the scanning direction
(also referred to as the carriage movement direction), and the ejection head 21 is
fastened to it (thus, the nozzles of the ejection head 21 intermittently eject ink
as they are moved in the scanning direction). The carriage 41 also removably holds
ink cartridges 48 and 49, which contain ink. The CR motor 42 is a motor for moving
the carriage 41 in the scanning direction, and is constituted by a DC motor. The CR
motor driver 43 is for driving the CR motor 42. The pulley 44 is attached to the rotation
shaft of the CR motor 42. The timing belt 45 is driven by the pulley 44. The guide
rail 46 is for guiding the carriage 41 in the scanning direction.
[0048] The measuring instrument group 50 includes a linear encoder 51, a rotary encoder
52, a paper detection sensor 53, and a paper width sensor 54. The linear encoder 51
is for detecting the position of the carriage 41. The rotary encoder 52 is for detecting
the amount of rotation of the carry roller 17A. The paper detection sensor 53 is for
detecting the position of the front end of the paper to be printed. The paper detection
sensor 53 is provided in a position where it can detect the position of the front
end of the paper S as the paper S is being carried toward the carry roller 17A by
the paper supply roller 13. It should be noted that the paper detection sensor 53
is a mechanical sensor that detects the front end of the paper S through a mechanical
mechanism. More specifically, the paper detection sensor 53 has a lever 53A that can
be rotated in the paper carrying direction, and this lever 53A is arranged so that
it protrudes into the path over which the paper S is carried. Thus the front end of
the paper S comes into contact with the lever 53A and the lever 53A is rotated, and
due to this, the paper detection sensor 53 detects the position of the front end of
the paper S by detecting the movement of the lever 53A. The paper width sensor 54
is attached to the carriage 41. The paper width sensor 54 is an optical sensor having
a light-emitting section 541 and a light-receiving section 543, and it detects whether
or not the paper S is in the position of the paper width sensor 54 by detecting light
that is reflected by the paper S. The paper width sensor 54 detects the position of
the edges of the paper S while being moved by the carriage 41, thereby detecting the
width of the paper S. The paper width sensor 54 can also detect the front end of the
paper according to the position of the carriage 41. The paper width sensor 54 is an
optical sensor, and thus detects positions with higher precision than the paper detection
sensor 53.
[0049] The control unit 60 is for controlling the printer 1. The control unit 60 has a CPU
61, a timer 62, an interface section 63, an ASIC 64, a memory 65, and a DC controller
66. The CPU 61 is for carrying out the overall control of the printer, and sends control
commands to the DC controller 66, the PF motor driver 16, the CR motor driver 43,
the pump motor driver 33, and the head driver 22. The timer 62 periodically generates
interrupt signals with respect to the CPU 61. The interface section 63 exchanges data
with a host computer 67 provided outside the printer 1. The ASIC 64 controls, for
example, the print resolution and the drive waveforms of the ejection head 21 based
on print information sent from the host computer 67 through the interface section
63. The memory 65 is for reserving an area for storing the programs for the ASIC 64
and the CPU 61 and a work area, for instance, and has storage means such as a RAM
or an EEPROM. The DC controller 66 controls the PF motor driver 16 and the CR motor
driver 43 based on control commands sent from the CPU 61 and the output from the measuring
instrument group 50.
[0050] When printing with such an inkjet printer 1, the paper S is intermittently carried
for a predetermined carry amount by the carry roller 17A, and in between those intermittent
carries, ink is ejected toward the paper S from the ejection head 21 while the carriage
41 moves in a direction that intersects the carrying direction of the carrying roller
17A, that is to say, in the scanning direction. Dots are formed on the paper S by
the ink that is ejected, and numerous dots are formed to produce an image on the paper
S.
=== Ejection Mechanism of the Ejection Head 21 ===
[0051] Fig. 5 is a diagram showing the arrangement of the nozzles for ejecting ink that
are provided in the lower surface section of the ejection head 21. As shown in the
diagram, nozzle rows 211, which are made up of a plurality of nozzles #1 to #13 for
each of the colors of black (K), cyan (C), magenta (M), and yellow (Y), are provided
in the lower surface section of the ejection head 21. It should be noted that from
among these colors, black (K) corresponds to an achromatic color, and cyan (C), magenta
(M) and yellow (Y) correspond to chromatic colors. The nozzles #1 to #13 are arranged
in a straight line in the carrying direction of paper 7. The nozzle rows 211 are positioned
parallel to one another with spaces between them in the movement direction (scanning
direction) of the ejection head 21. The nozzles #1 to #13 are provided with piezo
elements (not shown) as drive elements for ejecting droplets of ink.
[0052] When a voltage of a predetermined duration is applied between electrodes provided
at both ends of a piezo element, the piezo element expands for the duration of the
voltage application and deforms a lateral wall of the ink channel. As a result, the
volume of the ink channel is constricted by an amount corresponding to the expansion
of the piezo element, and ink corresponding to this amount of constriction becomes
an ink droplet, which is ejected from the relevant color nozzle #1 to #13.
[0053] Fig. 6 shows a drive circuit of the nozzles #1 to #13. As shown in the diagram, the
drive circuit is provided with an original drive signal generation section 221, a
plurality of mask circuits 222, and a drive signal correction circuit 223. The original
drive signal generation section 221 creates an original signal ODRV that is shared
by the nozzles #1 to #13. As shown in a lower portion of the diagram, the original
signal ODRV is a signal that includes two pulses, a first pulse W1 and a second pulse
W2, during the main scanning period of a single pixel (during the period that the
carriage 41 crosses over a single pixel). The original signal ODRV created by the
original drive signal generation section 221 is output to each mask circuit 222.
[0054] The mask circuits 222 are provided corresponding to each of the plurality of piezo
elements that drive the nozzles #1 to #13 of the ejection head 21. The mask circuits
222 receive the original signal ODRV from the original signal generation section 221
and also receive print signals PRT(i). The print signals PRT(i) are pixel data corresponding
to pixels and are binary signals having two bits of information for a single pixel.
The mask circuits 222 are for blocking or allowing the original signal ODRV to pass,
depending on the level of the print signal PRT(i). That is, when the print signal
PRT(i) is level "0," the pulse of the original signal ODRV is blocked, but when the
print signal PRT(i) is level "1," the pulse corresponding to the original signal ODRV
is allowed to pass as it is and is output to the drive signal correction circuit 223
as a drive signal DRV.
[0055] The drive signal correction circuit 223 performs correction by shifting the timing
of the waveforms of the drive signals DRV from the mask circuits 222. The width by
which the timing of the waveforms of the drive signals DRV, which are corrected here,
is shifted is adjusted as appropriate, based on instructions from the CPU 61 for example.
That is, based on instructions from the CPU 61 for example, the drive signal correction
circuit 223 can shift the waveforms of the drive signals DRV to a desired timing.
The drive signals DRV that are corrected by the drive signal correction circuit 223
are output to the piezo elements of the nozzles #1 to #13. The piezo elements of the
nozzles #1 to #13 are driven by the drive signals DRV from the drive signal correction
circuit 223 and eject ink. It should be noted that the drive circuit that includes
the original drive signal generation section 221, the plurality of mask circuits 222
and the drive signal correction section 223 corresponds to ejection control means
of the present invention.
[0056] In the inkjet printer 1 according to the present embodiment, such a drive circuit
for the nozzles #1 to #13 is provided for each of the nozzle rows 211, that is, for
each of the nozzle rows 211(K), 211(C), 211(M) and 211(Y) of the colors black (K),
cyan (C), magenta (M) and yellow (Y). Piezo elements of each nozzle row are driven
individually.
[0057] It should be noted that in the present embodiment, the ink that is ejected from the
ejection head is ink of the colors black (K), cyan (C), magenta (M) and yellow (Y);
however the present invention is not limited to these, and also includes cases in
which ink of other colors is ejected. Furthermore, the ink of the present invention
is not limited to colored ink, but includes transparent, colorless clear inks. Other
than these, in the present invention, liquids having special functions, whose object
is to be used in printing, and that are used in conjunction with these inks, are also
referred to as "ink" for convenience.
=== Processing by the Host Computer ===
[0058] Fig. 7 is a diagram for schematically describing the processing within the host computer
67. As shown in the diagram, the host computer 67 is provided by a computer 90, which
is connected to the printer 1, and a display device 93. A computer program 96 known
as a "printer driver" for controlling operation of the printer 1 is installed in the
computer 90. As shown in the diagram, the printer driver 96 is operated by an application
program 95 under a predetermined operating system that is installed on the host computer
67. A video driver 91 and the printer driver 96 are integrated into in the operating
system. Print data PD to be forwarded to the inkjet printer 1 is output from the application
program 95 via the printer driver 96. The application program 95, which carries out
retouching of images, for example, performs desired processing with respect to an
image to be processed, and also displays the image on the display device 93 via the
video driver 91.
[0059] When the application program 95 issues a print command, the printer driver 96 of
the computer 90 receives image data from the application program 95 and converts the
image data into print data PD to be supplied to the inkjet printer 1. The printer
driver 96 is internally provided with a resolution conversion module 97, a color conversion
module 98, a halftone module 99, a rasterizer 100, a user interface display module
101, a UI printer interface module 102, and a color conversion lookup table LUT.
[0060] The resolution conversion module 97 performs the function of converting the resolution
of color image data formed by the application program 95 into the print resolution.
The image data that is thus converted in resolution is still image information composed
of the three color components RGB. The color conversion module 98 references the color
conversion lookup table LUT as it converts the RGB image data pixel-by-pixel into
multi-gradation data of a plurality of ink colors that can be used by the printer
1.
[0061] The color-converted multi-gradation data has a gradation value of 256 scales, for
example. This data is subjected to so-called "halftone processing" by the halftone
module 99, creating halftone image data. The halftone image data is rearranged by
the rasterizer 100 into the data order in which it is to be transferred to the printer
1, and is output as the final print data PD. The print data PD includes raster data
indicating how dots are formed during each main scan and data indicating the sub-scan
amount.
[0062] The user interface display module 101 has a function for displaying various types
of user interface windows related to printing and a function for receiving user inputs
in those windows.
[0063] The UI printer interface module 102 functions as an interface between the user interface
(UI) and the printer 1. It interprets instructions given by users through the user
interface and sends various commands COM to the printer 1, or conversely, it interprets
commands COM received from the printer 1 and performs various displays on the user
interface.
[0064] It should be noted that the printer driver 96 executes, for example, a function for
sending and receiving various types of commands COM and a function for supplying print
data PD to the printer 1. Such a program for executing the functions of the printer
driver 96 is supplied in a format in which it is stored on a computer-readable storage
medium. Examples of this storage medium include various types of media from which
the host computer 67 can read data, such as flexible disks, CD-ROMs, magneto optical
disks, IC cards, ROM cartridges, punch cards, printed materials on which a code such
as a bar code is printed, internal storage devices (memories such as a RAM or a ROM)
and external storage devices of the host computer 67. The computer program can also
be downloaded onto the computer 90 via the Internet.
=== Borderless Printing ===
[0065] The inkjet printer 1 of the present embodiment has, as a print mode, a borderless
printing mode in which "borderless printing" is performed, in addition to a normal
print mode in which printing is carried out normally.
[0066] The normal printing mode is a mode of printing in which a print region P fits in
on the paper S. Fig. 8 shows the relationship between the print region P and the size
of the paper S in normal printing mode. As shown in the diagram, the print region
P is set so as to fit within the paper S, and a blank space is formed on the peripheral
section of the paper S, that is, on both the left and right edge sections and on both
the top and bottom edge sections.
[0067] If the printing mode is set to normal, then the printer driver 96 creates print data
PD based on image data obtained from the application program such that the print region
P fits within the paper S. If image data whose print region P cannot fit within the
paper S is to be processed, then a portion of the image that is expressed by the image
data may be excluded from being printed, or the image may be reduced in size, for
example, so that it fits on the paper S.
[0068] On the other hand, the "borderless printing mode" is a mode of printing by which
no blank space is formed on the paper S. Ink is also ejected into a region that is
outside the paper S. Fig. 9 shows the relationship between the print region P and
the size of the paper S in the "borderless printing mode". As shown in this diagram,
in the "borderless printing mode", the print region P is set such that it is larger
than the paper S. There are cases in which a blank space may not be formed in the
peripheral section of the paper S, that is to say, on both right and left edge sections,
and on both top and bottom edge sections of the paper S. It should be noted that it
is not necessary that a blank space is formed on both right and left edge sections
and both top and bottom parts of the paper S as shown in Fig. 9, but may also only
be formed in one part of the paper S.
[0069] When the mode is set to the "borderless printing mode", the printer driver 96 can
generate print data PD such that the print region P protrudes beyond the paper S.
Here, if image data whose print region P becomes smaller than the paper S is to be
processed, then the print region P can be expanded such that it covers the entire
paper S. In this way, it is possible to carry out printing that has a superior appearance
and that has no borders.
< Processing Ink that has Missed the Medium >
[0070] There is the possibility that the ink that has missed the paper S in the "borderless
printing mode" will have adverse effects such as soiling the platen 14. Therefore,
the printer 1 according to the present embodiment is provided with an ink recovery
section 80 to recover such ink.
[0071] Fig. 10 and Fig. 11 show an example of the ink recovery section 80. Fig. 10 is a
cross-sectional view showing the ink recovery section 80, and Fig. 11 is a plan view
showing the ink recovery section 80. As shown in Fig. 10, the ink recovery section
80 is formed on the platen 14 as a groove section 82 that has a concave cross section.
As shown in Fig 11, the groove section 82 is arranged in a straight line in the movement
direction of the carriage 41(scanning direction). Absorbing material 84 is arranged
within the groove section 82 to absorb the ink that has been discarded. The absorbing
material 84 is formed from various materials that are capable of absorbing the ink,
such as sponge for example. The ink that is discarded can be absorbed by the absorbing
material 84 when it reaches the absorbing material 84.
[0072] The ink that is recovered by the ink recovery section 80 is only the ink that is
ejected from the nozzles #5 to #9, which are arranged in opposition to the ink recovery
section 80, of among the nozzles #1 to #13 that are provided on the ejection head
21. The other nozzles, that is, nozzles #1 to #4 and #10 to #13 are not arranged in
opposition with respect to the ink recovery section 80, and thus the ink that is ejected
cannot be recovered by the ink recovery section 80. That is to say, the nozzles #1
to #4 and #10 to #13 are not used during "borderless printing", and only the nozzles
#5 to #9 are used for printing.
[0073] It should be noted that in Fig. 10 and Fig. 11, the groove section 84 is only provided
in a single position; however the present invention is not limited to this case, and
groove sections may also be provided in a plurality of positions, such as in the paper
feed direction (carrying direction) or in the scanning direction, for example.
=== Ink whose Ejection Amount is Reduced ===
[0074] In the inkjet printer 1 according to the present embodiment, the ejection amount
of some types of ink (liquid) is reduced if there is a possibility that such ink will
reach a region outside the medium, even with "borderless printing". That is to say,
the amount of ink of some types of ink, of among the inks ejected by the inkjet printer
1, that is ejected toward the region that is outside the medium is reduced.
[0075] The following are examples of inks whose ejection amount is reduced.
(1) Ink whose permeability is lower than other inks.
(2) Ink whose permeability decreases on contact with other inks.
(3) Ink that lowers the permeability of other inks on contact therewith.
[0076] Here, "(1) Ink whose permeability is low" means ink whose permeability is low with
respect to materials such as paper or sponge that are generally absorptive with respect
to liquids. More specifically, this includes inks that, for example, have absolutely
no permeability with respect to absorptive material for reasons such as their molecule
being large, or which are permeable with respect to such material but whose permeation
speed is slow and which take a long time to for the liquid to permeate. Of course
this is not limited to cases in which the entire components of the ink have a low
permeability, and even if the permeability of one or more components of the composition
is low, then it is regarded as an "ink whose permeability is low". For example, there
are cases in which the permeability of the solvent of the ink is high, but the permeability
of components such as pigments contained therein is low.
[0077] Furthermore, "(2) Ink whose permeability decreases on contact with other inks" means
ink whose individual permeability is high, but whose material characteristics change
on contact with other ink causing a decrease in permeability. More specifically, there
are inks that cause chemical reactions on contact with other ink, causing a reduced
permeability. In a similar manner to "(1) Ink whose permeability is low", such ink
includes ink that has absolutely no permeability with respect to paper for example,
and ink that is permeable with respect to the material, but whose permeation speed
is slow and which thereby takes a long time to permeate. Here as well, of course,
the case is not limited to that in which the entire composition of the ink has a low
permeability after contact, and if even some components of the composition have low
permeability, then this is regarded as an "ink whose permeability is low".
[0078] Furthermore, "(3) Ink that has a characteristic of lowering the permeability of other
inks on contact therewith" includes, for example, inks that cause a chemical reaction
on contact with other ink and that cause acceleration in coagulation of the other
ink, so as to create a coagulate compound with the other ink.
[0079] When the inks (1) to (3) miss the medium S and are recovered in the ink recovery
section 80 during borderless printing, there is the possibility that they will not
readily permeate into the absorbing material 84 in the ink recovery section 80, and
will remain behind. When the ink remains on the absorbing material 84, the ink accumulates
and begins to pile up, and detrimental effects such as soiling of the medium S during
printing or obstruction of the movement of the ejection head 21 can be expected to
arise. In order to prevent occurrence of such detrimental effects, the printer 1 of
the present embodiment is arranged so as to reduce the ejection amount of the inks
(1) to (3) if there is a possibility that they will reach the region that is outside
the medium S.
=== Processing in the Printer Driver ===
[0080] When the print mode is set to "borderless printing mode", the printer driver 96 generates
print data PD such that the print region P protrudes beyond the medium S during creation
of the print data PD based on image data obtained from the application program. However,
as previously described, for ink that may possibly cause problems such as build-up
if it reaches the region that is outside the medium S, if there is a possibility that
it will reach a region that is outside the medium S, then the printer driver 96 creates
print data PD such that the ejection amount is reduced.
[0081] Fig. 12 shows an example of the ejection state of the ink that may possibly cause
problems if it reaches a region that is outside the medium. The region in which the
ink is ejected, that is, the print region P, has a normal ejection region P1 and an
ejection amount reduction region P2. The normal ejection region P1 is a region in
which ink is ejected without any reduction in the ejection amount. The ejection amount
reduction region P2 is a region in which ink is ejected with its ejection amount reduced.
The ejection amount reduction region P2 is a region where there is a possibility that
ink will reach a region that is outside the medium S, that is to say, it is provided
from the outer periphery of the paper (medium) S to a part that protrudes beyond the
exterior of the paper S.
[0082] Here, as the method for reducing the ejection amount of ink in the ejection amount
reduction region P2, there are methods such as reducing the amount that is ejected
from each nozzle per time (per one drop), or performing thinning-out, for example.
If the ejection amount per time (per one drop) is to be reduced, then print data PD
is created such that a smaller dot will be formed. Furthermore, in the case of performing
thinning-out, the print data PD is created such that at a predetermined interval,
ink droplets are not ejected.
[0083] It should be noted that for ink of types other than those which may cause problems
if they reach a region outside the medium, print data PD is created such that such
that the print region P protrudes beyond the medium S, as shown in Fig. 9.
[0084] Furthermore, the ejection amount reduction region P2 that is set here does not necessarily
have to be arranged such that it protrudes beyond the paper S as shown in the diagram,
and it can be set on the peripheral section of the paper S with a certain degree of
leeway.
[0085] Furthermore, the "region that may reach the region that is outside the medium" is
set by the printer driver 96 etc. based on information about the paper S, such as
the size of the medium (paper) S that is to be printed or detection information from
various sensors.
[0086] Furthermore, the process of providing the ejection amount reduction region P2 as
described previously for the ink that may cause problems if it reaches the region
that is outside the medium can be carried out when the data is converted into multi-gradation
data for each ink color by the color conversion module 98, or when it is subjected
to halftone processing by the halftone module 99.
[0087] As described above, for the ink that may cause problems such as accumulation if it
reaches the region that is outside the medium S, if there is a possibility that such
ink will reach the region that is outside the medium, then print data PD is created
such that the ejection amount is reduced. In this way, the amount that reaches the
region that is outside the medium S can be reduced, and thus it is possible to achieve
a reduction in the problems that this type of ink causes when it reaches the region
that is outside the medium. That is to say, with the inkjet printer 1 of the present
embodiment, the amount of accumulation on the absorbing material 84 of ink, among
the inks that are ejected from the ejection head 21, that has a possibility of accumulating
on the absorbing material 84 when it is recovered by the absorbing material 84 of
the ink recovery section 80 is reduced when performing "borderless printing mode".
Thus, it is possible to eliminate problems such as soiling of the medium that is printed
and obstruction of the movement of the ejection head 21 caused by the ink that has
piled up on the absorbing material 84 of the ink recovery section 80.
=== Other Methods for Reducing the Ejection Amount ===
[0088] Fig. 13 is a diagram that describes an example of a case where the ejection amount
is set to zero for ink that may cause problems if it reaches the region that is outside
the medium S, without providing an ejection amount reduction region P2 such as that
shown in Fig. 12. Here, for the ink that may cause problems if it reaches the region
that is outside the medium S, the print region P is arranged such that the print region
P does not protrude beyond the medium S.
[0089] It should be noted that the print region P arranged here can be set such that it
fits just within the size of the paper S, as shown in the diagram, or it can be provided
with some leeway, such that a blank space is provided on the peripheral section of
the paper S. Of course, the print region P can also be set such that it is provided
with a sufficient blank space, as in the "normal printing mode" described previously
and shown in Fig. 8.
[0090] In this way, as for ink that may cause problems in case it reaches the region that
is outside the medium S, if there is a possibility that the ink will reach the region
that is outside the medium S, then ejection is kept from being performed by setting
the ejection amount to zero, instead of reducing the ejection amount. Thus, problems
that are caused when such ink reaches the region that is outside the medium can be
reliably eliminated.
=== Other Methods For Borderless Printing ===
[0091] In the "borderless printing" described in Fig. 9, the print region P was set such
that it was larger than the paper S; however, it is not absolutely necessary to execute
such a method when performing "borderless printing".
[0092] Fig. 14 is a diagram that describes another example of a method for "borderless printing".
As shown in the diagram, the print region P is provided up to the very limit of the
region of the paper S. Even if such a print region P is set to the very limit of the
region of the paper S in this way, printing can be performed such that only a minimum
blank space is formed in the edge section of the paper S.
[0093] Fig. 15 is a diagram that describes an example of a method for setting the ejection
amount reduction region P2 for ink that may cause problems if it reaches the region
that is outside the medium S with respect to the above-described method for "borderless
printing". Here, the ejection amount reduction region P2 is provided on the peripheral
section of the paper S. Furthermore, the normal ejection region P1 is provided on
the inner side thereof, surrounded by the ejection amount reduction region P1.
[0094] In the case of the method for "borderless printing" shown in Fig. 14, it is also
possible to set the ejection amount reduction region P2 to be the region that is the
very limit of the peripheral section of the paper S as shown in Fig. 15. Such a region
is set to the very limit of the peripheral section of the paper S because there is
a possibility that the ink may reach the region that is outside the medium S if positional
displacement of the paper S occurs. For ink that may cause problems if it reaches
the region that is outside the medium S, the occurrence of problems can be reduced
by reducing the amount of ink ejected with respect to such regions.
=== Methods for Verifying Permeability ===
<Methods for Verifying Permeability (1)>
[0095] An example of a method for verifying the permeability of the ink is described next.
Fig. 16 is a diagram for describing an example of the verification method. Verification
is performed by providing a groove section 82, which is assumed as an ink recovery
section, as shown in the same diagram, arranging a sponge as the absorbing material
84 within the groove section 82, and dripping ink IP from above onto the sponge 84.
Comparison is made by dripping the same type of ink IP onto the same point of the
sponge 84 at a predetermined time interval for a predetermined number of times. The
amount of ink IP that is dripped per time is set to be the same. For example, the
condition is set such that drops of 25 pl are dripped 200 times at 1 second intervals.
[0096] Whether or not the ink remains on the sponge 84 is confirmed by sight etc., or the
amount of ink that remains on the sponge 84 is determined from the height H and size
(diameter M), for example, of ink T that remains on the sponge 84. Such an investigation
is carried out for different types of ink, for example, for different colors. From
the result, if the ink remains on the sponge 84, or if the height H or size (diameter
M), for example, of the ink T exceeds a predetermined reference, or if it is comparatively
larger than another ink, then it can be established that the ink is low in permeability.
<Methods for Verifying Permeability (2)>
[0097] Next, verification methods for when one of the ink decreases in permeability when
two types of ink are placed in contact with one another, and for when an ink accelerates
coagulation of another ink, are described. Even in such cases, in a similar manner
to the verification method (1), verification is performed by dripping ink IP from
above onto a sponge 84 that is arranged as the absorbing material inside a grooved
section 82, which is assumed as an ink recovery section 80, as shown in Fig. 16. However,
in this method, two types of ink are used, and comparison is made by dripping these
two types of ink for a predetermined number of times at a predetermined time interval
onto the same point. The amount of ink IP that is dripped per time is set to be the
same. For example, the condition is set such that drops of 25 pl are dripped 200 times
at 1 second intervals. At this time, it is also preferable to investigate examples
in which the two types of ink are dripped individually, as comparative examples.
[0098] Accordingly, whether or not the ink remains on the sponge 84 is confirmed by sight
etc., or the amount of ink that remains on the sponge 84 is determined from the height
H and size (diameter M), for example, of ink T that remains on the sponge 84. Such
an investigation is carried out for different types of ink, for example, for different
colors. From the result, it is verified whether or not the permeability of ink has
decreased based on the presence/absence of ink remaining on the sponge 84, or by comparing
the height H and the size (diameter M), for example, of the ink T with a predetermined
reference or other inks.
=== Configuration of Liquid Ejection System Etc. ===
[0099] The following is a description of a printing system, as an example of a liquid ejecting
system according to the present invention, provided with an inkjet printer as a liquid
ejecting apparatus.
[0100] Fig. 17 is an explanatory diagram showing the external structure of the liquid ejecting
system. A liquid ejecting system 1000 is provided with a computer 1102, a display
device 1104, a printer 1106, an input device 1108, and a reading device 1110. In this
embodiment, the computer 1102 is accommodated within a mini-tower type housing; however,
there is no limitation to this. A CRT (cathode ray tube), a plasma display, or a liquid
crystal display device, for example, is generally used as the display device 1104,
but there is no limitation to this. The printer 1106 is the printer described above.
In this embodiment, the input device 1108 is a keyboard 1108A and a mouse 1108B, but
it is not limited to these. In this embodiment, a flexible disk drive device 1110A
and a CD-ROM drive device 1110B are used as the reading device 1110, but the reading
device 1110 is not limited to these, and it may also be a MO (magnet optical) disk
drive device or a DVD (digital versatile disk), for example.
[0101] Fig. 18 is a block diagram showing the configuration of the liquid ejecting system
shown in Fig. 17. An internal memory 1202 such as a RAM within the housing accommodating
the computer 1102 and, also, an external memory such as a hard disk drive unit 1204
are provided.
[0102] A computer program for controlling the operation of the above printer can be downloaded
onto the computer 1000, for example, connected to the printer 1106 via a communications
line such as the Internet, and it can also be stored on a computer-readable storage
medium and distributed, for example. Various types of storage media can be used as
this storage medium, including flexible disks FDs, CD-ROMs, DVD-ROMs, magneto optical
disks MOs, hard disks, and memories. It should be noted that information stored on
such storage media can be read by various types of reading devices 1110.
[0103] In the above description, an example was described in which the computer system is
constituted by connecting the printer 1106 to the computer 1102, the display device
1104, the input device 1108, and the reading device 1110; however, there is no limitation
to this. For example, the computer system can be made of the computer 1102 and the
printer 1106, or the computer system does not have to be provided with one of the
display device 1104, the input device 1108, and the reading device 1110. It is also
possible that the printer 1106 has some of the functions or mechanisms of the computer
1102, the display device 1104, the input device 1108, and the reading device 1110.
As an example, the printer 1106 may be configured so as to have an image processing
section for carrying out image processing, a display section for carrying out various
types of displays, and a recording media attachment/detachment section to and from
which recording media storing image data captured by a digital camera or the like
are inserted and taken out.
[0104] In the embodiment described above, it is also possible for the computer program for
controlling the printer to be taken into the memory 65, which is a storage medium
of the control unit 60. Also, the control unit 60 may execute the computer program
stored in the memory 65 so as to achieve the operations of the printer in the embodiment
described above.
[0105] As an overall system, the liquid ejecting system that is thus achieved is superior
to conventional systems.
=== Other Embodiments ===
[0106] In the foregoing, a printing apparatus such as a printer according to the invention
was described based on an embodiment thereof. However, the foregoing embodiment is
for the purpose of elucidating the present invention and is not to be interpreted
as limiting the present invention. The invention can of course be altered and improved
without departing from the gist thereof and includes equivalents. In particular, the
embodiments described below are also included in the liquid ejecting apparatus according
to the present invention.
[0107] In this embodiment, some or all of the configurations achieved by hardware may be
replaced by software, and conversely, some of the configurations that are achieved
by software can be replaced by hardware.
[0108] Furthermore, in addition to print paper, the medium to be printed may be cloth or
film for example.
[0109] It is possible to perform some of the processes that are performed on the liquid
ejecting apparatus side on the host side instead, and it is also possible to provide
a dedicated processing device between the liquid ejecting apparatus and the host and
perform some of the processes using this processing apparatus.
<Regarding the Liquid Ejecting Apparatus>
[0110] The liquid ejecting apparatus of the present invention can be adopted for printing
apparatuses such as an inkjet printer as described above, and in addition to these
it also can be adopted for color filter manufacturing devices, dyeing devices, fine
processing devices, semiconductor manufacturing devices, surface processing devices,
three-dimensional shape forming machines, liquid vaporizing devices, organic EL manufacturing
devices (particularly macromolecular EL manufacturing devices), display manufacturing
devices, film formation devices, and DNA chip manufacturing devices, for example.
<Regarding the Liquid>
[0111] The liquid of the present invention is not limited to ink, such as dye ink or pigment
ink, as described above, and it is also possible to adopt liquids (including water)
including metallic material, organic material (particularly macromolecular material),
magnetic material, conductive material, wiring material, film-formation material,
electronic ink, machining liquid, and genetic solutions, for example. Moreover, as
regards the constituents of the liquid, the liquid can also be made of solvents such
as water and dissolving agents.
<Regarding the Medium>
[0112] As regards the medium, it is possible to use plain paper, matte paper, cut paper,
glossy paper, roll paper, paper, photographic paper, and rolled photographic paper,
for example, as the paper described above. In addition to these, it is also possible
to use film material, such as OHP film or glossy film, cloth material, and sheet metal
material, for example. In other words, any medium may be used, as long as liquid can
be ejected onto it.
Industrial Applicability
[0113] According to a principal feature of the present invention, it is possible to achieve
a liquid ejecting apparatus, a liquid ejecting method, and a liquid ejecting system
that are capable of reducing problems caused when a certain type of liquid, from among
the plurality of types of liquids that are ejected from a liquid ejecting section,
reaches a region that is outside a medium.
[0114] Furthermore, according to another principal feature of the present invention, it
is possible to achieve a liquid ejecting apparatus that is capable of reducing problems
caused when a certain type of liquid, from among the plurality of types of liquids
that are ejected from a liquid ejecting section, reaches a region that is outside
a medium.